Top reaming-machine.



F. A. STEVENSON. TOP REAMING MACHINE APPLICATION f'luzu MAR. 4, 1916.

Patented. Feb-12, 1918.

8 SHEETS-SHEET l.

' v In vantor .Frederick A. Stevenson F. A STEVENSON. TOP REAMINGMACHINE. APPLICATION FILED MAR. 4, 1916.

Patented Feb. 12, 1918.

8 SHEETS-SHEET 2.

Z'IIiiIIIKII 52 1 III!!! F. A STEVENSON. TOP REAIVHNG MACHINE.APPLICATION FILED MAR. 4. 191a.

1,56,7 .Pzxtented Feb.12,1918.

8 SHEETS-SHEET 3.

Big. 6.

[n 116M502 FrederMAflevems0n F. A STEVENSON.

TOP REAMING MACHINE.

APPLICATION FILED MAR. 4. 191a.

Patented Feb. 12,1918.

8 SHEETS-SHEET 4.

Inverzzar A. Sieverzsam F.-A STEVEN-SON TOP REAMING MACHINE. APPLICATIONFILED MAR.4. 19\6- Patented. Feb. 12, 1918.

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142 66 144 Q Q 143 5 g5 55 56 fnvenzfor F. A STEVENSON. TOP REAMINGMACHINE. APPLlCATlON FlLED MAR. 4. l9.\6.

Patented Feb.12,1918.

8 SHEETS-SHEET 7.

v r 'IIIIIIIIlIIIIII/III Inventor Freda/2' ch14. Stevenson F..ASTEVENSON.

TOP REAMING MACHINE.

APPLICATION FILED MAR. 4. I916.

1,%'6,@72 Patented Feb.12,1918.

Y B SHEETSSHEET 8.

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z Q2 Q Inventor fiederidfl. Stevenson To all whom it may concern: 7

Be it known that I, FREDERICK A. STEVEN- soN, residing at Detroit,Michigan, and being a citizen ofthe United States, have invented certainnew and useful Improve:

ments in lop Beaming-Machines, ofwhich the following is a full, clear,and exact description, such as will enable others skilled in the art towhich it appertains to make and to use the same, reference being had tothe accompanying drawings, which illustrate the preferred form'of theinvention, though it is to be understood that the invention is g exactdetails or" construction shown and described except as required 7 by thescope of the appended claims, ash; is

ent in obvious that varlous modifications thereof will occur to personsskilled in the art.

In said drawings:

Figure 1 'is a transverse sectional View throng such a car buildingtrack as is presv the Detroit shops of the American Car & FoundryCompany, and shows mounted thereupon my improved reaming machinetogether with the pneumatic and electrical supply connections.

enlarged scale, through ofiny reaming machine, showing the pneu- 1'0ig.-e.

' Fig 8, showing the valve thereto.

Fig. 2 is a plan view of a portion of Fig. 1. ig. 3 is an end elevationshowing the end of the traveler of my reaming machine.

Fig. 4 is an elevational View of the upper portion of my reamingmachine, parts of the traveler being broken away and some parts beingshown in section.

Fig. 5 is an elevational view of those parts shown in Fig. 6 is avertical ce tral section on an he upper portion matic arrangements Fig;7 is a horizontal section taken on line 7-.,7;of'Fig.6. V

Fig. 8*is a vertical section taken on line shows the valve controllingtheair conditions in the air cylinder *Fig. is. a vertical section 3 online 9-9 of jin conditionfor admitting air to the air cylinder.

5 10-10 of -F1g. 8, sh

1 otherv ports for-the valve.

Q] F g; '10 is another Vertical section on line owing the relation of-F1g. 11 is a plan view of the valve: some cated in dotted lines.

Specification of Letters Patent. Application filed March 4, 1916. SerialNo.

, wheel sleeve trate, the arrangement of ig. 4, but viewed at rightangles drivlng elements and the adjustability of the reamer extension inplan.

line the valve housing beingindi o Fig. 30 --1s an enlarged viswillustrating Patented Feb. 12, 19118. 82,118.

Fig. 12 is a fragmentary elevational view of that side of the upperportion of the reaming machine which is opposite to that shown in thelower portion of Fig. 5.

Fig. 13 is a horizontal section on line Fig. 5 and Fig. 14 is anenlarged view of thelower portion of the reaming machine, those parts onthe right being principally shown in section. 1 Figs. 15, 16, 17 and 18are horizontal sec tions on lines 15--15, 1616, 17 -17 and 18-18,respectively, of Fig. 14, the switch being omitted in Fig. 18.

ig. l9 1s a horizontal section similar -to that shown in Fig. 18, butwith the hand removed to more clearly illusthe electrical conductorswhich run 'to racking motor switch. Fig. 20 is an elevation of the valveoperating handle, some parts being'sh'own in section. a

Fig. 21 is a horizontal ment of the valve operating handle, thecontinuance of the conductors shown in Fig. 19

reamer extension.

,Fi 2-1 is a fragmentary elevational View shownig the {upper portion ofthe reamer extension split.

Fig. 25 is a horizontal sdction showing the Fig. 26 is a fragmentarysectional view illustrating the upper end of the reamer spindle securedin the reamer motor spindle. Fig. 27 is a vertical section depicting themake and break switch 'located on the reamer upper yoke. .Fig. 28 is-anelevational view of the partsshown in Fig. 27, with the housing whichcarries the contact strip removed, and asviewed at right angles to Fig.27.

Fig. 29 is a horizontal section taken on 29-29 of Fig. 27.

swtion on line -2I2l of Fig. 14, and shows the arrangewith the contactstrips carried by the overhead box glrder of the car building struc-'ture.

" injuries are constantly occurring is usually upwar chine hereindisclosed, the

- used in hand reamers may Fig. 32 is a vertical section on line 32-32of Flg. 31 and shows the contact rollers attached to the dependingsupport from the traveler. horizontal section taken on Fig. 33 is a line33-33 of Fig. 31, showing one of the the contact strip,

contact rollers engaging Fig. 34 is a diagrammatic view of theelectrical circuits em odied in the reaming machine.

My present inventlon relates to reaming machines and particularly tothat type which is used for reaming holes vertically in car parts, suchas under-frames.

Fig. 1 illustrates such mounted upon an overhead structure constitutingwhat is known'as a building track in the car building industry, and thisfigure has been constructed substantially in accordance with anarrangement -1n service in the Detroit shops of the American Car &Foundry, Company.

Heretofore it has been customary in reaming work to employ hand reamers,the use of which necessitated two operators, whereas with the machineherein disclosed a single operator is all that is required. In reamingan under-frame, for example, it has been usual for two men to stand uponthe underframe, and to grasp handles projecting from the reamer motorcasing. At best, the footing of the operators on skeleton-like work wit]uneven surfaces is precarious, and the weight of the hand reamingmachine, which d of 100 lbs., is such that it iswith great diflicultythat they are able to swirg the old type reamer from one hole to bereamed to another, an at the same time be sure that they are maintaininga proper footing to manipulate this unwieldytool.

To keep the weight of hand reamers within such limits that the workmencan manipulate" them with any facility at all, their sizes andhorsepower are restricted to an undesirable degree. In the reamingmalifting is pneumatically accomplished and a reaming motor severaltimes more powerful than those be employed, improving the character andincreasing the amount of work performed. I 1 It is a matter wellrecognized that serious during of the conditions such operations becausefrequently either just spoken of, and very chain, and

a reaming machine vention to or both operators are injured upon atendency of the reamer bit to. stick in the work. When said reamer bit,and consequently the parts that rotate with it,becomes wedged, or forany reason tends to stop rotating, the reamer casing, which is also amotor casing and supposed to remain relatively stationary, begins torotate upon the armature in the reamer motor becoming stationary, and,as this occurs unexpectedly, the operators are frequently thrown fromthe car, sustaining in many instances inju' ries which not onlyincapacitate them for further work, but often result in fractured limbsor heads.

who are engaged in reaming operations, andgreater facility in performingwork is ofiered by having the weight of the reaming tool supported insuchway as to relieve the operator from contending with it. It has beenfound that, in view of the perfect safety and the relief from laboriouseffort, a greater amount of work can be performs in a given time thanhas been possible through the prior practice, and the manufacturing costis materially lessened.

It is also anobject to permit, what will hereinafter be termed, thereamer-bit, and those parts from which it is supported, to be movedwithin certain limits, which limits include a substantial zone, so thatholes within that zone may be reached and reamed without moving andtraveler, hereinafter more opening and closing of the reamer motorcircuit, relieving the operator of the necessity cuit. It is also thepurpose of the present inhave the device act that the reamer bit willapproach the work rapidly, without loss of time, but, when about toream, to automatically adjust itself to a proper feeding of the reamerbit through the hole to be reamed.

Care has been taken to so design the parts, that the wires of theelectrical circuits-will not become tangled becahse of the relativemovement between certain of the parts and. for example, the hand wheelmay be turne at will without in any way disturbing the electricalconnections between the parts which remain relatively stationary duringsuch turning of wires be s'ecured to parts ,therewith.

Asthe reaming machine is adapted for general use and different pieces ofwork are subjected to its treatment, a reamer extension device isincorporated therein whereby the reaming bit may be adjusted to thealti-' 'tudes of the various planes of any given that do not turnfeature is the automatic a hole in of changing the condition in thiscirpromptly so I the hand wheel, though the eaders piece of work. Otlferadvantages becoming apparent hereinafter are all to be consideredas'coming within the scope of the present invention.

Referring specifically to the parts, and first consulting ig. 1, 1indicates the col,- umns of .the building track overhead structure,disposed on opposite sides of the rails 2, constituting the buildingtrack. The columns 1 on each side of the rails 2 are usually spaced"suitable distances apart longitudinally of sad building track rails andsup port box girders 3, and mounted upon each box girder is a rail 4. j

Said rails 4 constitute a track for a traveler 5, which traveler may beof any suitable design, but in the form shown comprises a pair ofchannels 6 substantially, spanning the distance between the rails 4, andshorter end channel members 7 connecting channel 6 and extendingtherebeyond in opposite directions. x

Secured to and projecting outwardly from the outer faces of channel 7,are bearings 8 for shafts 9 and 10. Shaft 10 is a'driven shaft andcarries a gear 11, meshing with- Which is a pinion 12011 the shaft of.the racking motor 13, which is-carried by suitable bracket 14, securedtoone of the channels 6. Shafts 9 and 10, after passing through thebearings 8, project outwardly on each side pr the traveler far enough tocarry the traveler wheels 15, which are keyed or otherwise securedthereto, and are arranged to run on rails 4 of the traveler track. 7

The channels 6 of the traveler are spaced sufliciently apart to permitthe interposition of a trolley device, and the upper flanges of saidchannels .6 constitute tracks for the wheels of said trolley device.comprises preferably, 'a casting 16, better shown in Figs. 4, 5 and 6,and has side walls and inclined end-walls, the upper portions of whichextend somewhat above the traveler channels 6, and are formed at eachend intoa pair of bearings 17L Thelower portion 18 of the trolleycasting is cupshaped to form the socketof a ball and socket joint, andis suitably recessed to re-' ceive a lining of bearing metal 19, such asBabbitt Through each pair of bearings 17, at the opposite ends of thetrolley casting passes a shaft .20 for the trolley indicated in dottedlines in Fig. 6, the wheels are of the roller bearing type, permittingthe trolley as a whole to be very easily moved, and said trolley wheelshafts project beyond the outer faces of the wheels they support; saidwheels being held in place as by washers and cotter pins.- Said trolleywheel shaft-s 20 are also held from turning by set screws 22, passingthrough bearings 17 and biting the shaft, the roller bearing by a cap28, securely bolted thereto.

mounted thereon The latter serted into th wheels 21. As,v

wheels rota-ting easily about the therefore non-rotatableshafts 20.

As shown iii Fig. 6, a ball-joint casting has at its upper end ahemispherical form 23, and a lower cylindrical portion 24,'and issuspended from the trolley casting 16 by trolley casting 16 andlying inintimate contact with the bearing or Babbitt metal lining 19. The uppersurface of the hemispherical portion of the ball-joint casting has ahor1zontal annular flange forming a central circular opening. Mountedupon the flange of said hemispherical portion 23, is the flange of anair cylinder 25. The lower portion of the air cylinder projects throughthe central circular opening formed by the annular flange of thehemispherical portion 23 of the ball-joint casting, and is shaped into astufiing-box 26 provided with a gland 27.

The upper end of the air cylinder is closed With in the air cylinder isa piston comprising, by choice a leather piston gasket 29, disposedabove andbelow which are Washers 30, these parts surrounding a. tubularpiston rod 31, threaded atits upper end, a nut 32 being and screwedagainst the underside of the lower washer 30, while a piston cap 33 isscrewed upon the upper 'end of the tubular piston rod 31 closing thesame and pressing against the upper surface of the top Washer 30.

These parts are best illustrated in Fig. 6, where also the tubularpiston rod is seen to pass downwardly through the stuliing-box 26, whichis shown as projecting into the hemispherical 23 of the ball-jointcasting and as projecting further downwardly into the upper cylindricalportion 24 of said castin The lower end of the tubula'r piston rod 31,is screw-threaded and in- 'e upper portion of a--crosshead 34, thelatter having outstanding trunnions 35 and 36. e trunnion 35 ishorizontally drilled as at 37, the drilling extending to'the center ofthe cross-head 34, there also being a vertical drilling 38 centrally ofsaid cross-head opening into the first mentioned drilling 37. therebyestablished from the outer end of by means of a hole 39 with the spacein the air cylinder 25 which is present beneath the piston.

Trunnion 35'of cross-head'34 is also counterbored and threaded toreceive a. short pipe or nipple 40, to. which is secured an elbow, therebeing a pipe connection 41 from said elbow to an air valve 42 which ismounted upon another part, and with that part is to be later described.From the the box girders is mounted, to travel transversely of buildingtrack within the limits defined by thence to the air cylinder,

.ing 45 which piping,

being upturned sufficiently air. valve a pipe connection 43 extendsdownwardly and outwardly asshown in Figs. 4 and 6, the piping beingrelatively short and having secured to the end thereof an air hose 44.

As indicated in Fig. 1, said air hose 44 forms a loop and is ofsufficient length to permit the trolley in which the air cylinder the 3supported upon the columns 1. The upper end of said air hose 44 issecured to a down-turned portion of pipfor the most part, ishorizontally disposed and is secured to the outer face of the channel 6which is opposite the channel supporting the motor 13.

As shown in Figs. 1, 2 and 3, said piping 45 parallels the outer face ofthe channel 6 to which it is attached, and extends to the left until itapproaches the proximity of the left hand end of channel 7, here to passover an beyond said end channel 7 and also beyond the outer plane of thebox girder 3. To a short depending pipe extending beyond an elbow andforming a continuation of the conduit is another air hose 46 which inFig.1 is shown to be looped and is of suflicient length to permit thetraveler composed of channels 6 and 7 to traverse its track 4 in eitherdirection to the desired distances. Air hose 46 continues to and isconnected with an air piping 47 which extends longitudinally of thegirder 3- and is the usual air trunk line extending the entire length ofthe building track.

Reverse tracing of the air passages therefore discloses how the fluidpressure is transmitted from the source of air supply to the air valveof the reaming machine, and from and the purpose of the actuation of thepiston in the air cylinder is to raise and lower the reaming machinewhich move in unison with the reamer bit, as will be set forthhereinafter, the movement of such parts depending upon the actuation ofthe air valve 42.

To be seen in Figs. 5 and'6, the cylindrical portion 24 of theball-joint casting has oppositely disposed slots 48, the length of whichcorresponds substantially to the vertical travel of the reamer bit andthe parts that move therewith. Surrounding said cylindrical portion 24of the ball-joint casting," is a sleeve'portion 49 of the upper reamer.yoke, which sleeve portion is that member to which the air valve 42 issecured and with which it moves. In addition to sleeve portion 49, theupper reamer yoke comprises bracket arms 55 and motorinclosing frame 56,later referred to.

As seen in Figs. 4, 5 and 6, the upper end of the sleeveportion 49 ofthe upper reamer yoke is enlarged to a. greater diamethe parts ofextending from its upper surface d wardly, is provided with short slots51 at their upper ends, to of which slots the trunnions 35 and 36 ofcrosshead 34 ma the withdrawal of said trunnions from machine is inoperative assembly, clamp members52, having annular 51, when the tongues53, groove 50, in

* sleeve 49 of the upper vided and are bolted which ter and contains anannular groove 50,

set into the annular and own-

open

the lower portion y be earned. To prevent slots the enlarged portion ofthe continuous clamping annulus about sai larged upper 49 of the upnions 35 and said clamp members members in turn are and grooveconnection w1th per reamer yoke.

36 project through reamer yoke, cross-head 34 cannot be dentallywithdrawn.

When, upon the proper occasions, the piston in the air cylinder permitscrossdownwardly,

34 to move connection of clamps 52 to upper reamer move downwardly,

by reason of the reamer yoke, are protogether to form a d en-v head thecross-head through the the sleeve portion 49 of: the

yoke, said reamer yo the slots 48 in the tively stationary cylindricalportion 0 ball-joint casting permitting such ment. To protect tivemotion and the upper reamer mounted on trunnions said slots 48 in theball-joint trunnions also ser rollers and relative rotary joint castingand said up Preferably portion 49 of the depending trated in- Flgs.lower end the said dep between the yoke, rollers 54 are 35 and 36 andrun m the trunnions 3 casting.

movement between sai per reamer yoke. cast integral with the sleeve kewill relaf the move- 5 and 36 ote the ease of'relaball-joint casting aThe ve to prevent ballthe upper reamer yoke, are

bracket arms 55, clearly with the reamer motor inclosing and portingframe 56 Complementary to the upper reamer is a lower reamer y whichtially tending from the same contour gether by bolts. aresemi-cylindrical bea when the flanges are forth, form bearings fortrunmons sleeve 64,

bolted the sides of the casing o illus- 12 and 13, and at the endingarms merge supyoke oke, which comprises a motor supportihgframe 57,bracket arms 63 depending therefrom and a which the lower The upperportion of the reamer -motor supportmg is substantially like th tom ofthe upper reamer yoke,

with ends of said arms merge. said lower yoke f frame 57 at at thebotboth upper and lower reamer motor supporting frames being shownas'j-h'aving angular'reross section orms f the ing inwardly from bracketreamer motor 59, thereby suitably supporting said motor, the upper andlower reamer yokes forming a divisible motor-supporting frame, as isobvious from the drawings.

To more securely unite the upper and lowerreamer yokes, perforated lugs60 and 61 extend from the former and latter, respectively, and arejoined together by suitable -means, as properly retained pins 62.Converging as theyextend downwardly are the bracketarms 63' dependingfrom the reamer motor supporting fraine of the lower reamer yoke, saidbracket arms being united at their lower extremities by the sleeve 64.Extendarms 63, are steadying and positioning lugs 175, which hold thereamer motor 59 from any tendency to oscillate and thereby impartvibration to the reaming machine.

Threaded into the said bottom sleeve 64 is a bushing 65, indicated inFigs. 4 and 5 and well shown in Fig. 26, said bushing having. acentrally threaded bore into which is screwed a post, which post ispreferablyin the form of a pipe, said pipe post 66, bushing 65 andsleeve 64 being maintained in permanent relation by the set screw 67shown in Fig. 26. l

Referring to Figs. 1 and 14 particularly, pipe post 66 extendsdownwardly a proper distance to bring the lower portions of thereamingmachine into suitable juxtaposition to the work' to be treated.At its lower extremity a nut 67 is threaded onto the lower end of pipepost 66, said nut having an internal smoothbore adapted to serve as abearing for the lower solid end 68 of the reamer spindle. p

Figs. 14 and '26 disclose the type of reamer spindle which is employedin theform (if-reaming machine serving as a disclosure for thisinvention, it being clear that the upper end of the lower solid portion68 of the reamer spindle is reduced in cross section to fit Within apipe 69, constituting themajor portion of said reamer spindle, asclearly seen in Fig. 14. Consulting Fig. 26, the upper end of pipe 69 ofthe reamer" spindle is shown to receive a reduced lower end. of theupper solid portion 70 reamer spindle, said reduced portion terminatingin its upper part in a non-annular enlargement 71, fitting into acorrespondingly shaped recess in the bottom of the reamer motor spindle72, and terminating in a shank- 73 extending into said reamer motorspindle. .A nut 74'is screwed onto the exterior of the projectingportion of the reamer motor spindle to hold the reamer spindle inposition, and which nut, of course, is. re-

,movable to permit the withdrawal or changof the n f conimodates it,upon rotation of the reamer motor spindle, the'reamer spindle is causedto revolve. The mechanical connection between the upper and lowersolidportions 70 and 68 respectively, of the reamer spindle, to the pipeportion 69 may easily be made by welding these parts together.

The lower solid portion 68 of the reamer spindle has a considerablelength extending below its pipe inclosed reduced portion, a portion ofwhich telescopes within areamer extension member 75. The latter-partakesin general of the nature of a hollowcylinder, internally closed by a Webintermediate its upper and lower extremities, forming an upper pocketfor the reception of the solid reamer portion 68, and a lower pocket fora tapered sleeve 76, in this case a Morse tapered sleeve. The upper endof the reamer extension member is tapered as at 77, and split as shownin Figs. 24 and 25, to form spring gripping members, and below thetapered portion is a screw-threaded sub-division 78, adapted to receivea nut 79,

and which when screwed into place causes the split portions to firmlygrip the solid portion 68 of the reamer spindle, preventing longitudinalsliding of the reamer extension member upon said reamer spindle.

As it is desirable to apply considerablepressure to effect the bindingof these parts,

boththe nut 79 and the reamer extension 75 are provided with hexagonalformations for the application of-wrenches.-

.The clamping just described is not 1ntended for driving purposes, whichis accomplished by a key 80, shown in Fig. 23, which is inserted in anopening in the screwthreaded sub-division 78 of the reamer ex tensionmember, the key being threaded to complete the convolutions of thethreads in that portion of the reamer extension member ,and being forcedinto place-by a driving lit. Said key 80, extends into a key-way 81 inthe lower solid portion 68 of the reamer extension, as shown in Figs. 14and 23, insuring, the turning of the reamer extension member when thereamer spindle revolves;

As the height of the key is co-extensive with the height, of thethreaded portion 78 o the reamer extension member, and the key-way is ofconsiderable length, said eamer extension may be slid up and down aconsiderable distance, shortening or lengthening in efiect the reamerspindle and s then fixed in position by the tightening of nut 79. a

The tapered sleeve 76, which is inserted into t e lower pocket, hasprojections 82 which occupy conforming recesses in the bottom of saidreamer extension member, whereby when the reamer extension member isrotated in response to impulses from the reamer spindle, the saidtapered sleeve 76 will rotate with the Warner extension Inemher. Thelower end of the reamer extension member is also threaded to receiveanut 126, which holds the tapered sleeve securely 1n place. The shank ofa chuck 83 may at will be forced into the tapered sleeve, and, as isusual, has a tang 84 which projects into a slot in the top of thetapered sleeve and insures a positive drive of said chuck 83. Anydesired reamer bit may'then be inserted into the chuck after the commonpractice.

Considering Figs. 1, 14 and 21, a hand wheel 85 is shown, which isgrasped by the operator while l e is manipulating the reaming machine.By the use of this hand wheel he directs the point of the reamer bit toany desired hole, and upon the hand wheel is mounted an operating handlefor actuating air valve 42\ and a switch for controlling the rackingmotor 13, which moves the traveler to bring the reamer bit tosubstantially the longitudinal location of the hole to be reamed.

The valve operating in lugs 86 upon one of the handle is fulcrumedconformate with the curvature of the rim of the hand wheel bypreference, and having a rearwardly extending arm 88, as best seen in Fi20 and 21, which'at its inner end branc es and extends upwardly toembrace the outer faces of said fulcrumed legs 86.

- From the point of fulcruming another lever is bifurcated to armextends re'arwardly and upwardly and have legs 89 carrying at theirinner ends studs 90, which studs project into an annular groove 91 inthe bottom of switch cage 92. The lower end of said switch cage inclosesand rides upon a hand wheel sleeve 93, which is screwed to a flange onthe hub of the hand wheel 85.

When the operator grasps grip 87 of the valve operating lever and thejuxtaposed portion of the hand wheel rim and partially draws the handgrip toward said wheel rim, the bifurcated legs or arms 89 of the otherlever arm of the operating handle draws said switch,cage 92 downwardlyagainst the action of a spring to bepresently referred to, and when hereleases said hand grip 87 said spring causes the switch cage to moveupwardly.

The top of the switch cage as shown in Figs. 1, 14, 20 and 30 is.provided with a neck 94 which embraces the pipe post 66 in a slidingengagement, and extending from the neck 94 are diametrically opposedspaced lugs 95. Pivoted about pins supported in said lugs 95, areadjustable connection eyes best illustrated in Fig; 30. These eyescomprise cylinders 96 adapted to receive threaded eyes 97, to which areattached chain portions 98, which, upon rising to' a proper height mergeinto a single chain 99, the upper end of which is secured to a similarlyspokes of said hand wheel, and comprises a hand grip '87,

internally threaded 4 threaded eye .100 which is screwed into a clevis101, said clevis being pivoted to a valve lever 102 mounted on the stemof valve 42.

Lever 102 is a double armed lever and has attached to its opposite end ahelical spring 103. Thelowerend of said spring being secured to theupstanding flange of the upper reamer yoke supporting frame 56 as 1sclearly illustrated in Fig. 12.

It is therefore apparent that when the operator draws the grip handle 87upwardly toward the rim of the hand wheel 85, pulling down the switchcage 92, through the chains 98 and 99, he partially revolves lever 102,actuating the an valve handle 87, spring 103, attached to lever 102causes'said lever 102 to return to its original position. That the lever102 may not go beyond said initial position, a lever restraining chain104, having its lower end also secured to the upright flange, as shownin Fig. 12, of the upper reamer yoke supporting frame 56, is attached toa. screw eye 105, this being best shown in Fig. 30, threaded into aclevis 106 and terminates the .return movement of the lever 102 when theproper alinement of the valve and its ports for the initial position ofthe lever is obtained.

The use of the-chain devices which connect chains 98 to the switch cage92, and that which connects chain 99 to valve lever 102, and also thatwhich connects lever-restraining through the screw threaded eyes 97, 100and 105, perm'ts a fine adjustment between the switch cage chain 104 tosaid lever 102,

92 and said air valve lever 102,

enabling a very accurate setting of the valve therewith, as revlouslydescribed, said upair is being ad-- per reamer yo e, the lower reameryoke secured thereto and the reamer motor supported by both yokes, theparts.

and earned by the pipe post, which parts include all of the elements inthe lower part of the reaming machine, are raised to their uppermostpositions and so held by the fluid pressure exerted on the underside ofthe iston. The parts when sh held, are in theirout-of-use position,andthe valve 42 has its parts disposed as illustrated in Figs.

9' to 11 inclusive.

As seen in Figs. 8 and 9, the valve proper 107 1s of the ground taperedty a d the pipe post and'all of the reammg machine supported tains avalve pocket 108 of considerable width, narrowest toward the Ive andexpanding proaches the center of the angularly as it apuppercircumferential surface of said valve. Commumcating with the narrowestinnermost 109, two such 8 and 11, whereby vided for the Fig. 9 discloses109 and ports 111, is in the valve housing a sufiicient area ropipe 43,through housing 112 of a of the passages and also port 110 which and hasa width corresponding to that of pocket 108, which port 0 communicatesby 37 1n cross head hole passing by drilled piston 31 and entering t!plpe 41 to-the drilled 34, as shown in Fig. 6 hole 38 into the tubular1e space-in the air cylinder underneath the piston through hole sure iscontinuou source to keep the low said piston. 42 is in this conditlon,air pres- Therefore, while sly supplied from its piston in the aircylinder up, and thereby holding the movable parts, previouslyenumerated, of the ream- 1ng machine in their highest positions.

handle until the same has moved the operator has pushed as to carrythereamer bit Within the zone that does of the trollev or or both, bypulling upwardly on lve operating about, say,

one half its aruate stroke, the bifurcated arms 89, lever, through thealso parts of the valve operating studs 90-engaging annular recesses 91in the switch cage 92, causes sald cage 92, are pulled travel of thesaid switch cage to move down through part of its possible travel.

own in Fig. 30 and whlch to the chain lugs 95 at The chains 98 and downby the downward switch cage, causing. the

actuating lever 102 for a1r valve 42 to revolve through a portion tarymovement.

The operator 1s a movement to hand 'ing handle that thecounter-clock-wlse Fig. 9, shutting ofi' of its possible roaccustomed togive such grip 87 of the operatports 109 will move in a direction, asviewed in communication between port 111 in the bottom of the valvehousin of valve 107 into alinement witl pocket 108 in the in Fig. 10.

1 a pair of shown in dotted lines to in Fig. 8, and one being e 07 thenestablishes 001%- n pocket 108 and said rapidly exhausted through pipepost and all of the its possible travel, still ports 114 in the top ofthe valve housing 112, and due to the circumferential length of valvepocket 108 .this communication is extended in the opposite directionthrough pipe41, as seen in Fig. 6, througlg drilled holes 37 and. 38,the interior of piston rod 31, and by hole 39 t0 the interior of the aircvlinder 2 5..

'The air in said cvlinder 25 is therefore hole 39, tubular piston rod31, cross head 34, ipe 41, and as seen in Figs. 8, 10 and-11, t roughvalve housing port 110, passage 113, in the too of the valve 107 and outto atmosphere through the exhaust ports 114 in the valve housing 112.With the rapid exitof the air from the air cylinder, the piston underthe infiuence of the weight of the parts which are connected therewith,moves rapidly downwardly, as does the piston rod 31, cross head 34, theupper and lower reamer yokes, parts disposed therebelow, which includesthe reamer bit. As the reamer bit approaches the hole it is about toream, the operator pulls hand grip 87 of the valve operating lever,fulcrumed on the hand wheel, upwardly the rest of further pullingdownswitch cage Said switch cage thereupon draws chains 98 and 99, as bestshown in Figs. 12 and 30, further downwardly, swinging the valvelever-102 of valve 42 still further about its axis, so that the valve107 is further rotated in a counter-clock wise direction.

But a saw-cut 115 in municates with the passage 113 comes into alinementwith one of the exhaust ports 114 in valve housing 112. Therefore, because of the registration of saw-cut 115 with communicagreatlydiminished and the further downward advance of the parts, including thereamer bit is at a rate of speed best adapted to reaming purposes.

Difliculty is frequently experienced in keeping air valves tight, and toavoid any leakage of air through the valve, which would result in theparts whose positions are controlled special care is taken to preventany such leakage in valve 42. A valve cap 130 is screwed onto the outerend of the valve housing 112 and is of such vertical wall of said cap130 and against the sulating block, is a contact strip 125 of shoulderof valve 107 said spring 131 surless length than the travel of themovable rounding a stem 132 of the valve 107. Stem parts, including thecylindrical portion 49 132 projects through cap 130 and therebeof. theupper reamer yoke. As, in conseyond, and-slipped over it is a washer133,quence of exhausting the air in the air which is pressed by a nut 134against the cylinder 25, said cylindrical portion 49 of outer verticalfaceo-f cap 130. Suiiicient the upper reamer yoke moves downwardly,

ressure from jam nut 134 will cause washer it carries with it theinsulated strip 125,

133 to completely seal any points of e ress so that shortly after thebeginnin 0 t e 10 for the air and keep the same fully con ed downwardmovement of said cylindrical within valve 42. As, in service, constantportion 49 of the upper reamer yoke, enactuation of the valve may tend,after a gagement is made between contact strip 125 period, to disarrangethe adjustment of the and roller 117 causing the circuit in which jamnut 134, a lock nut 135 is provided, the reamer motor is included to beclosed,

15 which normally keeps jam nut '134 from as will be more fully shown ina diagramdisplacement, but in case of which, m y be matic wayhereinafter. For the present it backed w y fro th j m t 134 til a issuificient to say that the circuit is closed new adjustment of said jamnut 134 is made, and a the motor begins to operate an again causingwasher 133 to seal the valve, that operation is carried on throughoutthe 20 whereupon lock nut 135 on mor h ld downward movement of thecylindrical porthe jam nut 134 properly in place. tion of the upperreamer yoke and the rest It being necessary that the reamer bit reof themovable reamer parts throughout volve to perform the reaming operation,most of the continuance of their downward means have been providedwhereby the travel. But before they quite complete I '25 reamer motorwill haveits circuit closed their downward travel, the upper end. of

and begin to impart rotary motlon to the contact strip 125 passes belowand away reamer bit. That the operator may not from contact roller 117of the contact plunbe called upon to exercise his judgm t s ger device,breaking the circuit and cansto when to begin or to cease the running ofmg the reamer motor to become inoperative. 30 thereamer motor, amake-and-break switch When the air valve 42 is again operated to ismounted upon the cylindrical portion 49 admlt into the air cylinder 25,thereby of the upper reamer yoke, the loc tion of causing the piston inthat cylinder to draw this make-and-break switch being show i up thoseparts susceptible to upward travel, Figs. 4, 5, 27,28 and 29, itsdetails being a reverse action between .the contact strip 35 disclosedin the last three fi res. 125 and contact roller 117 takes place, andBest seen in Figs, 27 an 28, a lot 116 .the motor again revolves untilthe contact is formed in the cylindrical portion 49 of strip 125 andcontact roller 117 again the upper reamer yoke, into the lower porassumethe position shown .in Fig. 27, tion of which slot projects a contactroller whereupon the motor is once more stopped 40 117, mounted in aplunger 118, a part of and so remains until another hole is to be whichplunger is inclosed in what is shown reamed. as a square casing 119,though it may have While operating, the motor sets up a conother form,and projecting through the rear siderable torque, which tends to giverotary A end thereof and forming a binding post 120, movement to thehemispherical portion of 45 a spring 121 within square casing 119backthe ball-joint casting and the parts of the ing said plunger andnormally causing said reaming machine which are suspended thereroller117 to extend outwardly. Said square below by the reaction through saidparts. casing 119 is inclosed by an insulating cas- Means to obviate thedanger of this is proing 128, this casing being forced into the vided;and comprises a lurality of lugs 136,

50' wall of the lower cylin rical ortion 24 extending outwardly mm thecup-s aped of the ball-joint casting by a riving fit, socket portion 18of the trolley casting, and and thoroughly ins lating the contact rollerchains 137 secured toeye bolts in the ends of device from that casing. vsaid lugs 136 at one end, and at the other Because of slot 116, theupper reamer end secured. to eye bolts screwed into the 55 yokecylindrical portion 49 and all of the ball-joint casting intermediatethe hemis- 120 l movable parts are capable of moving downphericalportion 23 and the lower cylindrical wardly. without interference bysaid conportion 124. Saidchains 137 are installed tact. roller device.,Attached to a raised so as t6 have a small degree of slacknem soslot-outlining port on f the cylindrical that the hemispherical portion23 of the 60 portion of the upper reamer yoke is a cover ball-jointcasting may freely oscillate with- 122 secured to the cylindricalportion 49 of. in the cup-shaped'portion 18 of thetrolley the up erreamer yoke'by screws 129, and casting 16, but which slack may quicklybe secure to this cover 122 by screws 123 is taken up .and prevent anymore than a very an insulating block 124. In turn secured I slightinitial rotation of the said ball-joint 65 by countersunk head bolts127, to the'incasting vgithin an trohey casting. a o

. the track upon to move in the .necessary to incline the w 66 by setscrews 141, and has The chain lugs 136 perform another function in thatsome of them extend under-.

wheels 21 of the trolley from ever accidentally jumping off the uppflanges of said channels 16, Which constitute which they run.

1 While the depending portion of the reaming machine may be oscillatedwithin a certain zone to reach various holes therein, occasions arisewhen the reaming tool must be carried to another of Work, particularlywhen it is lengthy and wide as is the underframe of a railway car.

0 far as the operator is concerned, to accomplish such a change ofposition it is but necessary for him to press either one of two buttonsin the racking motor switch, if it is necessary to move the traveler 5,which 9 a switch-box 139 formed as an intergral part of the rim of handwheel 85.

Pressing one button causes the traveler composed of channels 6 and tomove in one direction, and pressing the other button, oppositedirection. The longitudinal position of any hole to be reamed may belocated by this means. secure the transverse location, the operatorsimply pushes against the pipe post 66, and because ofthe easy runningof the wheels 21 of the trolley 16, upon the channels 6 of the traveler,the reaming machine will be carried transversely over the work until theoperator ceases pushing. Also due to the easy movement of the trolley,when it is suspended reamer machine parts, as indicated by dot and dashlines in Fig. 1, to reach zone the reamer bit is then located in, andthe reamer bit into said fectly perpendicular to the work.

eferring again to hand Figs. 14 and 20) the latter is revoluble, so thatthe valve operating lever and the racking motor switch may be carriedaround by hand to any position the operator may change to, rendering itunnecessary to have more than one of each of these devices upon the handwheel. That this may be so, a hand wheel collar 140, is secured to pipepost an upper portion of enlarged diameter, recessed to receive the hub142 of 142 of the hand Wheel contains in its lower portion an annulargroove 143, into which project set screws 144 threaded into the handwheel collar 140. Said screws 144 prevent any vertical displacement ofthe hand Wheel, but allow it to turn freely under the influportion ofthe piece a hole within the Figs. 4 and 12, wheel 85, (see the handWheel 85. Said hub ence of the operators hand as he Walks about from oneposition to another.

It is of course Wiring to the reamer motor 59, the makeand-break switchmounted drlcal portion 49 of the upper reamer yoke and to the rackingmotor switch 138 on the hand wheel, and also to a controller box 145mounted on the outer face of the traveler channel 6, shown in Figs. 1and 2, on the same side of said traveler as rackin motor 13, and to amagnetic switch box 146 adjacent the controller box 145, as well as tocontact rollers 147 which collect current for the entire electricalwiring of the machine from contact strips 148. Said contact strips 1 8are mounted upon an insulating strip 149 carried by the web of the Ibeam, forming the inner surface of one of the box girders 3, and saidcontact strips 148 and that length of the overhead car buildingstructure which is allotted to the work to be erformed.

onsidering the mechanical arrangement of the wiring to the variouselectrical devices just enumerated, and consulting Figs. 1 and 2, cables150 run from the controller and magnetic switch boxes 145 and 146 alongthe outer surface of the channel 6 of the traveler which supports saidboxes, to and through one of the end channels 7, the left hand one inFigs. 1 and 2, one of said cables going to said current collectingcontact roller devices 147, and the others running-along the face ofsaid end channel 7 of the traveler, again through the same and along theouter face of the opposite traveler channel 6, being bound to the airpiping 45, to the central portion of the last mentioned traveler channel6, here being bound to air hose 44 and progressing with it to the piping43 which leads to the inlet side of air valve 42, as shown in Figs. 4and 12.

Considering Fig. 5 in connection with it will be seen in Fig. 4 that oneof the cables, designated from this point as 151 runs up alongside thecover 122 of the make-and-break switch, to and into the ball-jointcasting at the enlarged portion intermediate the hemispherical andcylindrical portions 23 and 24 respectively.

As indicated in Fig. 27, cable 151 runs down inside of the cylindricalportion 24 of the ball-joint casting toward binding post 120, and one ofits Wires 154is connectvalve 42, as seen in Fig. 4, and runs to abinding post 153 which extends inwardly to contact strip 125 of themakevand-break switch, serving to hold said contact strip to itsinsulating block 124, as do bolts 127. The actual electrical circuitnecessary to carry electrical will be better disclosed diagrammaticallya 3 an insulating) sleeve 163, and brushes 164,

a 165 and 166 ea .25

' the upper reamer and socket 156, an

later on. Y

Reverting to Figs. 4 and 12, another cable 155 passes through thebracket arm 55 of oke and down to a plug emerging from the plug portionthereof, runs to the reamer motor 59. A third cable 157 extends, as se nin Figs. 4, 5- and 12, from adjacent the piping 43 to the other leg 55of the upper reamer yoke, through a flange thereof and down to a plugand socket-158, and from the plug portion of said socket, down one leg63 of the lower reamer yoke and into a plpe conduit 15 9.

As seen in Figs. 1 and 14, pipe conduit runs to and into switch cage 92,the cable 157 emerging therefrom with its three wires divided and going161 and 162. These contact rings are shown in Fig. 14, in section at theright and 1n dotted lines at the left, to be mounted upon r against saidcontact rings and are supported upon another insulating sleeve 167, setinto an annular recess in the upper portion .of the hand wheel sleeve93.

" Said insulatingsleeve 167 is secured to the hand wheel sleeve 93 byscrews 171, firmly A portion of the incarried by the hand sulatingsleeve 167,

Fig. 18, and in ,wheeLsleeve, is shown in I Fig. 17 the contact brushes164, 165 and 166 are shown in plan, one of them bearing against theuppermost contact ring 160.

Three .conductors 169 are secured to the said contact brushes 164, 165and 166; one

to each brush,,and pass down through long holes 168 in theseml-cylindrical ribs vert1-..

cally formed internally on the hand wheel sleeve 93, as bestshown inFigs. 14 and 18. Emerging from the lower end of the hand wheel sleeve93, one of the conductors 169,

seen in Fig. 14, passes into a spoke of the hand wheel 85, and the otherconductors 169 ass into spokes on the opposite sides of the firstmentioned spoke, through apertures therein, and in the first mentionedspoke, all three conductors now traversing the first mentioned spoke, asseen in'Figs. 19 and 21 over abridge 170, which supports them, into the.rim of the hand wheel85. As' seen in 169 passthrough the to the rackingmotor switch 138; the actual electrical circuits to be later betterdisclosed.

,The plug and. socket' devices supported upon the arms 55 of the upperreame'n yoke, permit a mechanical rupture of the wiring that runstoreamer motor 59 and racking motor switch 138 in the hand wheel vhen itis desired to disassemble the suspended parts of the reaming machine.

The pipe conduit 159 is secured to the pi e post 66 intermediate thelower reamer yo 0 or other means, and

switch cage is prevented tends into an elongated to three contact rings160,

' 1n the bracket 177 conforming to each which lead to the current andthe switch cage by clamps or brackets 172, fastened to pipe post 66 byset screws to prevent disruption cable 157, the

from rotating c about the pipe post 66 by set screws 173, threaded intothe neck 94 of said switch cage, and extending into slots 17 4 in the.pipe post, said slots being located within the switch cage 92 and are ofsuflicient length to permit'of free up and down travel of said switchcage, as best seen in Figs. 14 and 16.

Referring again to the current collecting contact rollers 147, andinspecting Figs. 31 to 33 inclusive, said contact rollers 147 are eachsupported in a plunger 176, which exbracket 177, the plunger 176 and therecess other that the plungers 17 6 may be properly guided. Eaqh plunger176 is spring pressed by a coil spring or other device 178, which nor- Imally presses the contact rollers 147 against the current supplyingstrips 148. r 90 The plunger brackets have their recesses opensubstantially throughout their outwardly directed faces, except for abacking wall for the springs 178, and said-recesses are closed by coverplates 179, held in place by screws passing therethrough and enteringthe plunger brackets 177. Both of the plunger brackets are mounted on aninsu-fi lating block 180, which in turn is secured by bolts to the lowerend of-a 'depending sheet metal or other bracket 181, carried by thetraveler 5, and the wires from the cable collecting roller contactdevices are conveniently secured, one to each of them.

To use the reaming machine, the main switch M shown in F1g. 34 is firstclosed, and current flows from the positive side of said main switch tothe positive current supply strip148, to the positive current collectlngroller 147, by conductor 'B,'through a fuse C, and by conductor which islocated another. fuse E, to theipnsitive side of starting resistance SR,through all of the same, and by conductor Gto the actuating coilofinterlocking rela H, to resistance Y, and by conductor to point J ,'byconductbrs' J 2 and J, through a fuse J, to conductor J F, throughanother fuse J ,-and

or tangling of the wires of contour of the by conductor J" tothenegative contact 1 roller 147, and by thenegative contact strip 148 tothe negative. side of i the mam switch M. a p

Interlocking relay actuating coil H is thereupon energize causing thebridging contact K to connect terminals LL.

If the operator now desires to movefth'e reammg machine longitudinallyof thework, m what mayibetermed a forward'direction', he turns'h sattention to the racking motor switch 138, which is located upon thehand Upon said closure of controller switch 1,

' wheel 85. Said racking motor switch 138 is current flows from thepositive side of the of the double switch type, and contains pushmam'switch M, to positive supply strip 148, button switches F an R. Toefi'ect said positive contact roller 147, conductor B, fuse forwardmovement of the traveler, comprisconductor D, fuse E, the remainder ofing channels 6 and 7, he closes switch F, conductor D, to and throughall of the conwhereupon current flows from the positive troller startingresistance SR, to one of the side of main switch M, to positive currentcontacts of controller switch 1, the bridging supplystrip 148,topositive contact rolle'r147, contact therefor, and the core of saidconby conductor B, fuse C, conductor D, fuse D, troller switch 1 and byconductor T to conductor D to contact ring 162, which is point T, thenceby conductor I, to and located within the switch cage, and by brushthrough resistance Y, and by conductor J, 166, and conductor D to oneside of switch to point J, by conductors J 2 and J to fuse F, throughsaid switch, and by conductor J by conductor J to fuse J and conduc- Fto brush 164, another ring 161, conductor J 7 to the negative contactroller 147, and tor F to points F and F here dividing thence by negativecontact strip 148 to the and going through the actuating coils Fnegative side of main switch M. This and F of reversing switches 1 and 3and causes .the short-circuiting of'the actuating continuing byconductor F which is concoil H of the interlocking relay H, and thenected'to the opposite ends of said actuatconsequent dee'ne'rgizing ofthe said actuing coils F 5 and F and runs to point N, ating coil Hresults in bridging contact K where the circuit branches, going throughof the interlocking relay H disengaging its small portions of tworesistances UU, and contacts LL.

by conductor F to one contact L, through After the throwing out of theinterlockbridging contact K, to the other contact L, ing relay H, asjust described, current is to point 0, to point'P, by conductor J, toflowing from the positive side of the main point J, thence by conductorsJ and J switch M to the positive contact strip 148,

to fuse J, conductor J to fuse J, conpositive contact roller 147,conductor B, fuse ductor 'J, to the negative side of main C, conductorD, fuse D, conductor D conswitch M. Actuating coils F and F of tact ring162, brush 166, conductor D reversing switches 1 and 3 now operate-tovthrough switch F, by conductor F, to brush close the latter switches. 3164,.to contact ring 161, and by conductor As a result, the currentcomes from the F to points F and F and to and through positive side ofthe main switch M, to posithe actuating coils F and F of reversing t1vesupply strip 148, to positive contact switches 1 and 3 by conductor F tobranch roller 147, and by conductor B, fuse C, conpoint N, here dividingand going through ductor D, fuse E, remainder of conductor all of theresistances UU, to points 0 and D, to the positive side of the startingresist- P, and by conductor J, to point J, thence ance SR, through saidresistance, and by by conductors J and J 3 to fuse J conducconductorD totheactuating coil O of tor J fuse J conductor J to negative controllerswitch 1", by conductor D", to the contact roller 147, and by negativecontact racking motor series field A and by con-v strip 148 to thenegative side of the main ductor D, to and through the now closed switchM, the said reversing switches 1 reversing switch 3 by conductor Qtoconand 3 being held closed by the establishtact Q of open reversingswitch 2 and ment of the just described circuit. by conductor Q? to thearmature A of the As controller switch 1 had previously racking motor13, by conductor A to conclosed, the starting resistance SR, betweentact S of opened reversing swltch 4, by concontroller switches 1 and 2became shortductor S to contact S of closed reversing circuited, and, inthe racking motor cirswitch 1*, through said switch and by coneuit,current flowed from the positive side ductor J to fuse J by conductor Jfuse o the main switch M to positive contact J conductor J to negativecontact roller strip 48, positive contact roller 147, con- 147, and bynegative co ntact str1p 148, to ductor B, fuse C, conductor D, fuse E,the the negative side of main switch M. The remainder of conductor D, tothe starting racking motor 13 thereupon is started with resistance SR,through the latter to one conall of the start1n resistance SR incircuit. tact ofcontroller switch 2 through the actu- The hereinbe orementioned controller ating coil C of said controller switch 2", switch 1which is included in the circuit to the contacts of the now closedcontroller last traced, is of a magnetlc type, and for switch 1',through the actuating coil C a short time is magnetically restrainedfrom of the latter, by conductor D to the rackclosing, but as the motorspeeds up, the curing motor series winding A by conductor rent passingthroug i actllfltlng 0011, C, D, to and through the now closed reversandwhich initially possessed a considerable ing switch 3, by conductor Q,to contact overload value, is diminished to its normal Q of openedreversingswitch' 2, by con- ,value and controller switch 1 closes;ductor Q to the armature A] of racking remaining in sec motor 13, byconductor 0 ened reversing switch 4', by conductor S tov contact S ofclosed reversing switch 1*, through said latter switch and by conductorJFto fuse J by conductor J 5 to fuse J, by conductor J to the negativecontact 'rollerj147, and by negative contact strip 148, to the negativeside of the main switch-Mr f After --'a preliminary pause, due to themagnetic" character of controller switch 2,

said switchcloses and current in the rackmotor circuit flows from thepositive side of the main switch M,'to positive contact strip 148',positive contact roller 147, by conductor B fuse C, conductor D, fuse E,the remainder of conductor D, to and through the small amount ofresistance SR the racking motor circuit, through theurctuating coil C ofcontroller switch 3*, to the contacts of controller switch 2", throughthe actuating coil of said controller switch, to the contacts ofcontroller switch 1', through the actuating coil 0 of thelast mentionedcontroller switch, and by conductor D to' and through: the motor seriesfield- A pf racking motor 13,'by conductor D". to and through closedreversing switch 3, by conductorQ to contact Q, of opened reversingswitch 2, by conductor Q te -the armature A of racking motor 13, by,nductor A to contact S of open reversing' switch 4, by conductor S tocontact S of closed reversing switch 1*, through said switch and ,byconductor J to fuse J, by conductor J to fuse J, by conductor J tonegative contact roller 14? and by negative contact strip 148-to thenegative side of the main switch After being magn a short period oftime, controller switch 3 closes and all of the racking motor controllerresistance SR is cut out of the racking motor circuit, and rackingmotor, 13 is operating at full speed and causin eler, comprisingchannels 6 and% in what has been termed a forward direction. When thesuspended parts of the reaming machine have been moved so that thereamer bit is approximately at the lon 'tudinalpoint where the reamingisto be one, the operator opens switch F of the racking motor switch 138by taking his finger off the button by which switch F is closed,whereupon there is a resultant opening of the racking motor circuit andthe traveler comes to rest.

As the actuating coils F and For reversing switches 1 and 3 were incircuit with the said switch F, the opening of the latter switch causesthem to become deenergized, whereupon said reversing switches 1 and 3open, and, as the controller'switches 1 Wand-3 are in circuit with therevers- A to point S of etically restrained for the trav-' to move i'ngswitches 1 and 3*, become dead and said controller switches 1", 2 and 3open, leaving the electrical connections as they were before switch Fwas closed. This means that the main switch M alone is closed andcurrent flows from the positive side thereof to positive contact stri148, positive contact roller 147, conductor fuse O, conductor D, fuse E,remainder of conductor D, to and through all of the starting resistanceSR, and by conductor G to the actuating coil H, through resistance Y,and by conductor J to point J, and by conductors J 2 and J 3 to fuse Jconductor J fuse J conductor J negative contact roller'147, and bynegative contact strip 148 to the negative side of the main switch M.The bridging contact K of interlocking relay H therefore again con-.nects contacts LL, reestablishing the circuit that was originallyformed by the initial throwing in of main switch M before any otheroperation took place.

To bring the reamer location of the hole to be tor simply pushes reamed,the operaupon the trolley, carrying the suspended parts of the reamingmachine, will move transversely of, the work, and when the op eratorceases his pressure upon pipe post 66, the depending parts of thereaming machine will come to rest, and the reamer bit will beapproximately at the location of the hole to be reamed. 7 Any furthermoving of the reamer bit that may be necessary is accomplished by theoperator grasping hand wheel and directing the reamer bit toward said 0e. i His next step. is to partially actuate hand grip 87 of the valveoperating lever, mounted upon one of the spokesv of hand Wheel 85,stopping it at the point which allows the rapid exhaust of the air fromcylinder 25. Thereupon the piston rod 31 and cross head 34 move rapidlydownward, allowing the cylindrical portion 49 of the upper reamer yoketo slide downwardly over the lower cylindrical portion 24 of theball-joint casting, and therefore the lower reamer yoke, attached to theupper reamer parts depending therebelow, including the reamer bit,rapidly descend. As the reamer bit itself approaches the hole,the-operator pulls upwardly still further hand grip 87 of the operatinglever, mounted on hand wheel 85, and the air-valve 42 is furtheractuated, so that the minimized exhaust,previously described, sets in,and the reamer advances through the rest v of its downward stroke, at aproper reamingfeed speed.

Shortly after the upper cylindrical portion 49 of the upper reamer yokebegins to descend, contact strip 125 of the make-andbreak switchengagescontact roller 117 cartheir actuating coils on pipe post 66,where- H of interlocking relay bit to the transverse

